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1.
Acta Vet Scand ; 66(1): 26, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956712

RESUMO

Capnocytophaga canimorsus and Capnocytophaga cynodegmi are commensal bacteria in the oral cavities of dogs. Both are zoonotic pathogens that could infect humans via dog bites. C. canimorsus may cause life-threatening infections in humans, whereas C. cynodegmi infections tend to be milder and more localized. Capsular serovars A-C of C. canimorsus seem to be virulence-associated. Some of the C. canimorsus serovars described to date can also be detected in other Capnocytophaga species, including C. cynodegmi. The objective of this pilot study was to investigate the emergence of C. canimorsus and C. cynodegmi after birth in oral cavities of puppies and to evaluate the impact of the dam's Capnocytophaga spp. carrier status on the emergence. Ten litters, altogether 59 puppies, were included in the study. The puppies and their dams were sampled at five time points over seven weeks after whelping. Oral swab samples taken were investigated for the presence of C. canimorsus and C. cynodegmi by species-specific polymerase chain reaction (PCR), the specificity of which was verified by sequencing a selection of the PCR products. Samples that were positive in Capnocytophaga PCR reactions were also capsular-typed by PCR to gain more knowledge about the Capnocytophaga spp. present in the samples. Altogether 10.2% and 11.9% of puppies, or 20.0% and 30.0% of litters tested PCR-positive for C. canimorsus and C. cynodegmi, respectively. Capnocytophaga PCR-positive puppy samples were always positive for only C. cynodegmi or C. canimorsus, not both. Most Capnocytophaga PCR-positive puppies became positive at the age of 5 to 7 weeks. Only a minority (5/16) of the C. cynodegmi PCR-positive dog samples were positive in capsular typing PCR, whereas all C. canimorsus PCR-positive dog samples were negative in capsular typing PCR. For all Capnocytophaga PCR-positive puppies, their dam was positive for the same Capnocytophaga species. These results suggest that puppies become colonized by C. cynodegmi or C. canimorsus from their dams at the time of deciduous teeth eruption.


Assuntos
Animais Recém-Nascidos , Capnocytophaga , Doenças do Cão , Infecções por Bactérias Gram-Negativas , Boca , Animais , Capnocytophaga/isolamento & purificação , Capnocytophaga/genética , Cães , Projetos Piloto , Boca/microbiologia , Animais Recém-Nascidos/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Infecções por Bactérias Gram-Negativas/microbiologia , Doenças do Cão/microbiologia , Doenças do Cão/diagnóstico , Feminino , Masculino
2.
FEMS Microbiol Lett ; 368(16)2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34410377

RESUMO

The COVID-19 (coronavirus disease 2019) pandemic has forced universities to find new ways to conduct learning and teaching, as traditional face-to-face teaching has been prevented or restricted to an absolute minimum in many instances. Therefore, we redesigned and taught second-year veterinary student microbiology laboratory exercises (labs) with a hybrid learning approach. For this, a novel 'remote partner' model was implemented in which students present on-site in the laboratory worked synchronously pairwise with their remote partner present online. A student feedback survey revealed that in this remote partner model, both on-site and online participation in the labs were experienced as being useful in improving their laboratory skills. The students' overall performance in hands-on microbiological laboratory skills and safe working practices was similar in the hybrid learning approach (the 2021 class) and in the traditional on-site participation approach (the 2018-20 classes). This study suggests that the remote partner model is an effective way to acquire microbiological laboratory skills. This learning approach can be used in the non-pandemic future and/or also be applied to other fields.


Assuntos
COVID-19/epidemiologia , Educação a Distância/métodos , Educação em Veterinária/métodos , Microbiologia/educação , COVID-19/prevenção & controle , Técnicas de Laboratório Clínico , Educação a Distância/organização & administração , Educação em Veterinária/organização & administração , Avaliação Educacional , Humanos , Modelos Educacionais , Ensino
3.
Front Microbiol ; 12: 688819, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34305849

RESUMO

Staphylococcus aureus is a highly prevalent cause of mastitis in dairy herds worldwide, capable of causing outcomes that vary from subclinical to peracute gangrenous mastitis. We performed a comparative genomic analysis between 14 isolates of S. aureus, originating from peracute bovine mastitis with very severe signs (9 gangrenous, 5 non-gangrenous) and six isolates originating from subclinical or clinical mastitis with mild to moderate signs, to find differences that could be associated with the clinical outcome of mastitis. Of the 296 virulence factors studied, 219 were detected in all isolates. No difference in the presence of virulence genes was detected between the peracute and control groups. None of the virulence factors were significantly associated with only a single study group. Most of the variation in virulence gene profiles existed between the clonal complexes. Our isolates belonged to five clonal complexes (CC97, CC133, CC151, CC479, and CC522), of which CC522 has previously been detected only in isolates originating from caprine and ovine mastitis, but not from bovine mastitis. For statistical analysis, we sorted the CCs into two groups. The group of CCs including CC133, CC479, and CC522 was associated with gangrenous mastitis, in contrast to the group of CCs including CC97 and CC151. The presence of virulence genes does not explain the clinical outcome of mastitis, but may be affected by allelic variation, and especially different regulation and thus expression in the virulence genes.

4.
Zoonoses Public Health ; 66(2): 207-215, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30536784

RESUMO

Practising veterinary medicine has an inherent risk of exposure to zoonotic agents, including the protozoan parasite Toxoplasma gondii. We screened sera of veterinarians authorized to work in Finland for the presence of specific immunoglobulin G antibodies against T. gondii with an enzyme-linked fluorescent assay, and evaluated potential risk factors for T. gondii seropositivity from extensive questionnaire data with almost 1,300 quantitative variables. We used a causal diagram approach to address the complexity of the life cycle of the parasite and its numerous possible transmission routes, and built a multivariable binomial logistic regression model to identify risk factors that are particularly relevant for veterinarians. The samples and questionnaire data were collected in 2009. Altogether, 294 veterinarians, almost 15% of the Finnish veterinary profession, were included in the study. The median age was 39 years, and the majority, 86%, were women. Altogether, 43 (14.6%; 95% confidence interval: 10.9-19.0) of the 294 veterinarians tested seropositive for T. gondii. According to the final model, veterinarians who were at least 40 years old had 2.4 times higher odds to be seropositive than younger veterinarians; veterinarians who lived in the countryside had 4.0 times higher odds to be seropositive than veterinarians who lived in towns; female veterinarians who tasted beef during cooking had 2.6 times higher odds to be seropositive than male veterinarians who did not taste beef during cooking; and veterinarians who did not do small animal practice had 2.3 times higher odds to be seropositive than those who did. The results illustrate the numerous transmission routes of T. gondii.


Assuntos
Anticorpos Antiprotozoários/sangue , Carne Vermelha/parasitologia , Toxoplasmose/sangue , Médicos Veterinários/estatística & dados numéricos , Adulto , Fatores Etários , Animais , Culinária , Estudos Transversais , Feminino , Finlândia/epidemiologia , Parasitologia de Alimentos , Humanos , Imunoglobulina G/sangue , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Estudos Soroepidemiológicos , Inquéritos e Questionários , Toxoplasma/imunologia , Toxoplasmose/epidemiologia , Toxoplasmose Animal/epidemiologia
5.
PeerJ ; 6: e4560, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29610707

RESUMO

Non-aureus staphylococci (NAS) are most commonly isolated from subclinical mastitis. Different NAS species may, however, have diverse effects on the inflammatory response in the udder. We determined the genome sequences of 20 staphylococcal isolates from clinical or subclinical bovine mastitis, belonging to the NAS species Staphylococcus agnetis, S. chromogenes, and S. simulans, and focused on the putative virulence factor genes present in the genomes. For comparison we used our previously published genome sequences of four S. aureus isolates from bovine mastitis. The pan-genome and core genomes of the non-aureus isolates were characterized. After that, putative virulence factor orthologues were searched in silico. We compared the presence of putative virulence factors in the NAS species and S. aureus and evaluated the potential association between bacterial genotype and type of mastitis (clinical vs. subclinical). The NAS isolates had much less virulence gene orthologues than the S. aureus isolates. One third of the virulence genes were detected only in S. aureus. About 100 virulence genes were present in all S. aureus isolates, compared to about 40 to 50 in each NAS isolate. S. simulans differed the most. Several of the virulence genes detected among NAS were harbored only by S. simulans, but it also lacked a number of genes present both in S. agnetis and S. chromogenes. The type of mastitis was not associated with any specific virulence gene profile. It seems that the virulence gene profiles or cumulative number of different virulence genes are not directly associated with the type of mastitis (clinical or subclinical), indicating that host derived factors such as the immune status play a pivotal role in the manifestation of mastitis.

6.
Front Microbiol ; 8: 657, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28450859

RESUMO

Lactobacillus ruminis, an autochthonous member of the gastrointestinal microbiota of humans and many animals, is a less characterized but interesting species for many reasons, including its intestinal prevalence and possible positive roles in host-microbe crosstalk. In this study, we isolated a novel L. ruminis strain (GRL 1172) from porcine feces and analyzed its functional characteristics and niche adaptation factors in parallel with those of three other L. ruminis strains (a human isolate, ATCC 25644, and two bovine isolates, ATCC 27780 and ATCC 27781). All the strains adhered to fibronectin, type I collagen, and human colorectal adenocarcinoma cells (HT-29), but poorly to type IV collagen, porcine intestinal epithelial cells (IPEC-1), and human colon adenocarcinoma cells (Caco-2). In competition assays, all the strains were able to inhibit the adhesion of Yersinia enterocolitica and enterotoxigenic Escherichia coli (ETEC, F4+) to fibronectin, type I; collagen, IPEC-1, and Caco-2 cells, and the inhibition rates tended to be higher than in exclusion assays. The culture supernatants of the tested strains inhibited the growth of six selected pathogens to varying extents. The inhibition was solely based on the low pH resulting from acid production during growth. All four L. ruminis strains supported the barrier function maintenance of Caco-2 cells, as shown by the modest increase in trans-epithelial electrical resistance and the prevention of dextran diffusion during co-incubation. However, the strains could not prevent the barrier damage caused by ETEC in the Caco-2 cell model. All the tested strains and their culture supernatants were able to provoke Toll-like receptor (TLR) 2-mediated NF-κB activation and IL-8 production in vitro to varying degrees. The induction of TLR5 signaling revealed that flagella were expressed by all the tested strains, but to different extents. Flagella and pili were observed by electron microscopy on the newly isolated strain GRL 1172.

7.
Genome Announc ; 3(2)2015 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-25908141

RESUMO

Staphylococcus aureus is a major causative agent of mastitis in dairy cows. The pathogenicity of S. aureus may vary; it is able to cause severe clinical mastitis, but most often it is associated with chronic subclinical mastitis. Here, we present the genome assemblies of four S. aureus strains from bovine mastitis.

8.
BMC Vet Res ; 9: 227, 2013 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-24207012

RESUMO

BACKGROUND: Coagulase-negative staphylococci (CNS) cause usually subclinical or mild clinical bovine mastitis, which often remains persistent. Symptoms are usually mild, mostly only comprising slight changes in the appearance of milk and possibly slight swelling. However, clinical mastitis with severe signs has also been reported. The reasons for the differences in clinical expression are largely unknown. Macrophages play an important role in the innate immunity of the udder. This study examined phagocytosis and killing by mouse macrophage cells of three CNS species: Staphylococcus chromogenes (15 isolates), Staphylococcus agnetis (6 isolates) and Staphylococcus simulans (15 isolates). Staphylococcus aureus (7 isolates) was also included as a control. RESULTS: All the studied CNS species were phagocytosed by macrophages, but S. simulans resisted phagocytosis more effectively than the other CNS species. Only S. chromogenes was substantially killed by macrophages. Significant variations between isolates were seen in both phagocytosis and killing by macrophages and were more common in the killing assays. Significant differences between single CNS species and S. aureus were observed in both assays. CONCLUSION: This study demonstrated that differences in the phagocytosis and killing of mastitis-causing staphylococci by macrophages exist at both the species and isolate level.


Assuntos
Macrófagos/fisiologia , Fagocitose , Infecções Estafilocócicas/veterinária , Staphylococcus/imunologia , Animais , Bovinos , Células Alimentadoras , Feminino , Mastite Bovina/microbiologia , Camundongos , Camundongos Endogâmicos BALB C/imunologia , Infecções Estafilocócicas/microbiologia
9.
Acta Vet Scand ; 54: 69, 2012 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-23176642

RESUMO

BACKGROUND: The blaZ gene encoding penicillin resistance can be located either chromosomally or on plasmids. The aim of this study was to investigate the genetic relationships and to determine the location of the blaZ gene in S. aureus isolated in bovine mastitis in Finland and Sweden. METHODS: Seventy-eight ß-lactamase positive S. aureus isolates from bovine mastitis (34 from Finland and 44 from Sweden) were included in the study. The localization of blaZ gene was determined by Southern blotting. The blaZ genes of the isolates were sequenced and the sequences were translated to beta-lactamase proteins and further grouped as different protein signatures. The isolates and, as control, 33 Swedish and 36 Finnish beta-lactamase negative isolates were typed with pulsed-field gel electrophoresis (PFGE). RESULTS: In 26 out of 34 Finnish isolates (76.5%) and in 25 out of 44 Swedish isolates (56.8%) the blaZ gene was localized on a plasmid. Six different protein signatures were found. One signature was found only in four Swedish isolates, but all other signatures were found both in Finnish and Swedish isolates. The PFGE results revealed a diversity of S. aureus clones. The protein signatures were not clearly associated with certain pulsotypes. CONCLUSIONS: The plasmid location of the blaZ gene was not statistically significantly more common in Finland than in Sweden, and hence does not explain the higher proportion of penicillin-resistant isolates of S. aureus causing bovine mastitis in Finland compared to Sweden.


Assuntos
Mastite Bovina/microbiologia , Resistência às Penicilinas , Penicilinas/farmacologia , Plasmídeos/genética , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Animais , Southern Blotting/veterinária , Bovinos , Eletroforese em Gel de Campo Pulsado/veterinária , Feminino , Finlândia , Variação Genética , Filogenia , Plasmídeos/metabolismo , Reação em Cadeia da Polimerase/veterinária , Análise de Sequência de Proteína/veterinária , Infecções Estafilocócicas/microbiologia , Suécia , beta-Lactamases/genética , beta-Lactamases/metabolismo
10.
Int J Syst Evol Microbiol ; 62(Pt 1): 61-65, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21335502

RESUMO

Thirteen Gram-positive-staining coagulase-variable staphylococci were isolated from subclinical and mild clinical mastitic bovine milk (n=12) and a teat apex (n=1). The results of sequence analysis of the 16S rRNA gene and two housekeeping genes, rpoB and tuf, and DNA fingerprinting with amplified fragment length polymorphism (AFLP) analysis showed that the isolates formed a separate branch within the genus Staphylococcus. The phylogenetically most closely related species were Staphylococcus hyicus and Staphylococcus chromogenes. DNA-DNA hybridization with S. hyicus DSM 20459(T) and S. chromogenes DSM 20674(T) confirmed that the isolates belonged to a separate species. The predominant fatty acids were i-C(15:0), ai-C(15:0), i-C(17:0) and C(20:0) and the peptidoglycan type was A3α L-Lys-Gly(5). Based on the results of genotypic and phenotypic analyses, it is proposed that the thirteen isolates represent a novel species, for which the name Staphylococcus agnetis sp. nov. is proposed. Strain 6-4(T) (=DSM 23656(T)=CCUG 59809(T)) is the type strain.


Assuntos
Coagulase/metabolismo , Mastite Bovina/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus/classificação , Staphylococcus/isolamento & purificação , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Animais , Doenças Assintomáticas , Técnicas de Tipagem Bacteriana , Bovinos , Análise por Conglomerados , Impressões Digitais de DNA , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , RNA Polimerases Dirigidas por DNA/genética , Ácidos Graxos/análise , Leite/microbiologia , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Fator Tu de Elongação de Peptídeos/genética , Peptidoglicano/química , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Infecções Estafilocócicas/microbiologia , Staphylococcus/genética , Staphylococcus/metabolismo
11.
Anaerobe ; 16(3): 293-300, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19695336

RESUMO

In this study, a total of 94 lactic acid bacterial (LAB) isolates of porcine small intestinal and fecal origin were screened for their probiotic properties. The aim was to evaluate whether their isolation site and putative species identity play a role in these characteristics and whether either of these can be used as a predictive factor for the probiotic potential of bacterial isolates. The isolates were preliminarily identified by partial 16S rRNA gene sequencing and characterized in vitro for their pH and bile tolerance, adhesion capacity towards porcine enterocytes isolated from five intestinal sites and for antimicrobial activity towards five indicator pathogens. The interdependence of these characteristics was statistically evaluated. The isolates tolerated low pH and bile well. Adherence to the enterocytes of different origins did not correlate with the strain isolation site. In general, higher adherence was observed to colon cells in comparison to the small intestinal enterocytes. Culture filtrates of the isolates caused a decrease of up to three orders of magnitude in the intestinal pathogen cell numbers. The inhibition was mostly due to lactic and other organic acids. The predominating phylotypes identified were Lactobacillus reuteri and Lactobacillus salivarius, of which the former generally had the best adhesion capacity, whereas the latter appeared to be the best inhibitor. Based on the results, several strains of the pig Lactobacillus isolates tested may function as promising candidates for use in probiotic products. However, it was not possible to use the isolation site or the species identity of the isolates as reliable preliminary screening factors.


Assuntos
Intestinos/microbiologia , Lactobacillus/fisiologia , Probióticos , Animais , Aderência Bacteriana , Enterócitos/microbiologia , Fezes/microbiologia , Lactobacillus/isolamento & purificação , Suínos
12.
Int J Food Microbiol ; 124(3): 250-9, 2008 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-18456355

RESUMO

Thirteen storage trials and ten challenge tests were carried out to examine microbial changes, spoilage and the potential growth of Listeria monocytogenes in brined shrimp (Pandalus borealis). Shrimp in brine as well as brined and drained shrimp in modified atmosphere packaging (MAP) were produced and studied. Different recipes were used to study the effect of preserving parameters (organic acids, pH and NaCl) on growth of microorganisms and shelf life at 7-8 degrees C or 12 degrees C. Particularly, brines with different concentrations of (i) benzoic, citric and sorbic acids or (ii) acetic, citric and lactic acids were studied. Furthermore, the effect of adding diacetate to brined shrimp was evaluated. A single batch of cooked and peeled shrimp was used to study both industrially and manually processed brined shrimp with respect to the effect of process hygiene on microbial changes and the shelf life of products. Concentrations of microorganisms on newly produced brined shrimp from an industrial scale processing line were 1.0-2.3 log (CFU g(-1)) higher than comparable concentrations in manually processed samples. This resulted in a substantially shorter shelf life and a more diverse spoilage microflora of the industrially processed brined shrimp. In addition, shelf life of brined shrimp was affected by the types and concentrations of organic acids and by the storage temperature as expected. The effect of MAP was less pronounced. Eighty-two isolates from the spoilage microflora of brined shrimp were identified and they included 53 lactic acid bacteria, 6 coagulase negative Staphylococcus spp., 18 Pseudomonas fluorescens and 5 yeast isolates. After storage at 7 degrees C, P. fluorescens, Enterococcus-like isolates, E. malodoratus, Carnobacterium maltaromaticum, coagulase negative Staphylococcus spp. and Lactobacillus sakei constituted the dominating microflora of shrimp in brines that contained benzoic, citric and sorbic acids as preservatives. L. sakei dominated the spoilage microflora of brined and drained MAP shrimp, and of brined shrimp preserved using acetic, citric and lactic acids, irrespective of packaging conditions. Shrimp in brine with benzoic, citric and sorbic acids prevented growth of L. monocytogenes during more than 40 days at 7 degrees C when the preserving parameters resembled those of commercial products. However, small changes in the preserving parameters and, particularly, reduced concentrations of benzoic acid led to growth of L. monocytogenes in brined shrimp. The present study provides significant new information on microbial changes, shelf life and growth of L. monocytogenes in brined shrimp. This information can facilitate development of new and safe brined shrimp products.


Assuntos
Contaminação de Alimentos/análise , Embalagem de Alimentos/métodos , Conservação de Alimentos/métodos , Listeria monocytogenes/crescimento & desenvolvimento , Pandalidae/microbiologia , Frutos do Mar/microbiologia , Animais , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Higiene , Refrigeração , Fatores de Tempo , Vácuo
13.
Appl Environ Microbiol ; 73(4): 1136-45, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17142357

RESUMO

Some psychrotrophic lactic acid bacteria (LAB) are specific meat spoilage organisms in modified-atmosphere-packaged (MAP), cold-stored meat products. To determine if incoming broilers or the production plant environment is a source of spoilage LAB, a total of 86, 122, and 447 LAB isolates from broiler carcasses, production plant air, and MAP broiler products, respectively, were characterized using a library of HindIII restriction fragment length polymorphism (RFLP) patterns of the 16 and 23S rRNA genes as operational taxonomic units in numerical analyses. Six hundred thirteen LAB isolates from the total of 655 clustered in 29 groups considered to be species specific. Sixty-four percent of product isolates clustered either with Carnobacterium divergens or with Carnobacterium maltaromaticum type strains. The third major product-associated cluster (17% of isolates) was formed by unknown LAB. Representative strains from these three clusters were analyzed for the phylogeny of their 16S rRNA genes. This analysis verified that the two largest RFLP clusters consisted of carnobacteria and showed that the unknown LAB group consisted of Lactococcus spp. No product-associated LAB were detected in broiler carcasses sampled at the beginning of slaughter, whereas carnobacteria and lactococci, along with some other specific meat spoilage LAB, were recovered from processing plant air at many sites. This study reveals that incoming broiler chickens are not major sources of psychrotrophic spoilage LAB, whereas the detection of these organisms from the air of the processing environment highlights the role of processing facilities as sources of LAB contamination.


Assuntos
Contaminação de Alimentos , Microbiologia de Alimentos , Embalagem de Alimentos/métodos , Lactobacillaceae/fisiologia , Atmosfera , Manipulação de Alimentos , Ácido Láctico/metabolismo , Lactobacillaceae/metabolismo , Dados de Sequência Molecular
14.
Int J Food Microbiol ; 109(1-2): 164-8, 2006 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-16503360

RESUMO

Unidentified heterofermentative lactic acid bacterium (LAB) isolates detected earlier in vacuum or modified atmosphere (MA) packaged "Morcilla de Burgos", a Spanish cooked meat product, were identified in the present study. In the previous study, these strains had been studied by numerical analysis of HindIII RFLP- and phenotyping. However, neither of these methods had resulted in species identification. Even these unknown strains clustered together in the numerical analysis of the RFLP patterns, none of the typically meat-associated LAB type strains had clustered together with them. The phenotyping was not more useful; according to the criteria used these strains with similar HindIII ribopatterns should have been divided into four different species in three different genera. To establish the taxonomic position of these isolates, 16S rRNA gene sequence analysis, numerical analysis of EcoRI and HindIII ribopatterns, and DNA-DNA hybridization experiments were done. The 16S rRNA genes sequences of three isolates possessed the highest similarities with the corresponding sequences of Weissella species and in the phylogenetic analysis Weissella viridescens was their closest phylogenetic neighbor. However, in the numerical analysis of either HindIII or EcoRI ribopatterns the W. viridescens type strain did not cluster with these isolates. Nevertheless, the high (from 75% to 83%) DNA-DNA reassociation values between the strains studied and the W. viridescens type strain confirmed that these strains belong to the latter species. The somewhat divergent results of the pheno- and HindIII ribotyping indicate that W. viridescens is far more heterogeneous species than previously reported.


Assuntos
DNA Bacteriano/análise , Lactobacillus/classificação , Lactobacillus/isolamento & purificação , Produtos da Carne/microbiologia , Filogenia , Animais , Sequência de Bases , Análise por Conglomerados , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Lactobacillus/genética , Dados de Sequência Molecular , RNA Ribossômico 16S/análise , Ribotipagem
15.
Int J Food Microbiol ; 106(3): 318-23, 2006 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-16271788

RESUMO

Lactic acid bacteria (LAB) isolated from marinated or non-marinated, modified atmosphere packaged (MAP) broiler leg products and air samples of a large-scale broiler meat processing plant were identified and analyzed for their phenotypic properties. Previously, these strains had been found to be coccal LAB. However, the use of a 16 and 23S rRNA gene RFLP database had not resulted in species identification because none of the typically meat-associated LAB type strains had clustered together with these strains in the numerical analysis of the RFLP patterns. To establish the taxonomic position of these isolates, 16S rRNA gene sequence analysis, numerical analysis of ribopatterns, and DNA-DNA hybridization experiments were done. The 16S rRNA gene sequences of three isolates possessed the highest similarities (over 99%) with the sequence of S. parauberis type strain. However, in the numerical analysis of HindIII ribopatterns, the type strain did not cluster together with these isolates. Reassociation values between S. parauberis type or reference strain and the strains studied varied from 82 to 97%, confirming that these strains belong to S. parauberis. Unexpectedly, most of the broiler meat-originating strains studied for their phenotypical properties did not utilize lactose at all and the same strains fermented also galactose very weakly, properties considered atypical for S. parauberis. This is, to our knowledge, the first report of lactose negative S. parauberis strains and also the first report associating S. parauberis with broiler slaughter and meat products.


Assuntos
Microbiologia de Alimentos , Embalagem de Alimentos/métodos , Indústria de Processamento de Alimentos , Produtos Avícolas/microbiologia , Streptococcus , Microbiologia do Ar , Animais , Análise por Conglomerados , Qualidade de Produtos para o Consumidor , DNA Bacteriano/análise , DNA Bacteriano/genética , Contaminação de Alimentos , Indústria de Processamento de Alimentos/normas , Humanos , Fenótipo , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 16S/análise , Ribotipagem , Especificidade da Espécie , Streptococcus/classificação , Streptococcus/isolamento & purificação , Streptococcus/metabolismo
16.
Int J Syst Evol Microbiol ; 55(Pt 6): 2479-2484, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16280513

RESUMO

The taxonomic position of two bovine strains, LMG 13603 and LMG 14595, assigned to the species Enterococcus raffinosus on the basis of biochemical features, was reinvestigated. Both reference strains and two other isolates, 6/1 (=LMG 22829) originating from a charcoal-broiled river lamprey and IE38.4 (=LMG 22830) from the air of a poultry slaughter by-product processing plant, occupied a clearly separate position, on the basis of sequence analysis of the housekeeping gene pheS (encoding the phenylalanyl-tRNA synthase alpha-subunit), relative to the type strain of E. raffinosus and all other enterococcal species with validly published names. 16S rRNA gene sequencing of strains LMG 13603, LMG 14595, 6/1 and IE38.4 confirmed their phylogenetic position in the Enterococcus avium species group, there being more than 99 % 16S rRNA gene sequence similarity to most members of the group, including E. raffinosus, and revealed Enterococcus pseudoavium as the closest phylogenetic relative (99.8-99.9 %). Further phenotypic and genotypic analyses using whole-cell-protein electrophoresis, (GTG)(5)-PCR fingerprinting, ribotyping and DNA-DNA hybridization experiments demonstrated that all four strains represent a novel enterococcal species, for which the name Enterococcus devriesei sp. nov. is proposed. The type strain is LMG 14595T (=CCM 7299T).


Assuntos
Microbiologia do Ar , Enterococcus/isolamento & purificação , Aves Domésticas/microbiologia , Matadouros , Animais , Enterococcus/classificação , Enterococcus/genética , Enterococcus/fisiologia , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Filogenia , RNA Ribossômico 16S/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
17.
Appl Environ Microbiol ; 71(8): 4400-6, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16085830

RESUMO

Unidentified lactic acid bacterium (LAB) isolates which had mainly been detected in spoiled, marinated, modified atmosphere packaged (MAP) broiler meat products during two previous studies, were identified and analyzed for their phenotypic properties and the capability to produce biogenic amines. To establish the taxonomic position of these isolates, 16S rRNA gene sequence analysis, numerical analysis of ribopatterns, and DNA-DNA hybridization experiments were done. Unexpectedly for a meat-spoilage-associated LAB, the strains utilized glucose very weakly. According to the API 50 CHL test, arabinose and xylose were the only carbohydrates strongly fermented. None of the six strains tested for production of histamine, tyramine, tryptamine, phenylethylamine, putrescine, and cadaverine were able to produce these main meat-associated biogenic amines in vitro. The polyphasic taxonomy approach showed that these strains represent a new Lactobacillus species. The six isolates sequenced for the 16S rRNA encoding genes shared the highest similarity (95.0 to 96.3%) with the sequence of the Lactobacillus durianis type strain. In the phylogenetic tree, these isolates formed a distinct cluster within the Lactobacillus reuteri group, which also includes L. durianis. Numerical analyses of HindIII-EcoRI ribotypes placed all isolates together in a cluster with seven subclusters well separated from the L. reuteri group reference strains. The DNA-DNA hybridization levels between Lactobacillus sp. nov. isolates varied from 67 to 96%, and low hybridization levels (3 to 15%) were obtained with the L. durianis type strain confirming that these isolates belong to the same species different from L. durianis. The name Lactobacillus oligofermentans sp. nov. is proposed, with strain LMG 22743T (also known as DSM 15707T or AMKR18T) as the type strain.


Assuntos
Aminas Biogênicas/metabolismo , Embalagem de Alimentos/métodos , Lactobacillus/classificação , Lactobacillus/isolamento & purificação , Produtos Avícolas/microbiologia , Animais , Atmosfera , Técnicas de Tipagem Bacteriana , Composição de Bases , Galinhas/microbiologia , DNA Bacteriano/análise , Genes de RNAr , Lactobacillus/genética , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Fenótipo , Filogenia , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , Ribotipagem , Análise de Sequência de DNA
18.
Int J Food Microbiol ; 101(2): 145-52, 2005 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-15862876

RESUMO

Microbiological and sensory changes in vacuum-packaged charcoal-broiled river lampreys from three lamprey processing plants were monitored as a function of time at 8 degrees C. The lampreys were examined every 7 days up to 8 weeks for aerobic plate count (APC) and lactic acid bacteria (LAB). The highest mean APC and LAB were 6.01 log CFU/g and 4.86 log CFU/g, respectively. Only 6 out of 15 lots reached an APC value of 7.0 log CFU/g during storage. The sensory scores remained at the baseline levels after 8 weeks' storage. Twenty-seven isolates were randomly picked from MRS agar and identified to species level using a 16S and 23S rDNA HindIII RFLP (ribotyping) database and sequencing of the 16S rRNA gene if no database match was obtained. Twelve of the 27 isolates were identified as Lactobacillus curvatus subsp. curvatus, and two Leuconostoc mesenteroides and one Weissella halotolerans strain were also detected. Twelve isolates were not identified by the LAB database. However, they possessed very high (99.9%) 16S gene sequence similarity with either Staphylococcus warneri or Staphylococcus pasteuri type strains. The LAB detected, with the exception of W. halotolerans, have commonly been associated with spoilage of fishery products, but in these vacuum-packaged lampreys, they were not the dominant organisms within the developing spoilage population.


Assuntos
Bactérias Aeróbias/crescimento & desenvolvimento , Embalagem de Alimentos/métodos , Conservação de Alimentos/métodos , Lactobacillus/crescimento & desenvolvimento , Lampreias/microbiologia , Alimentos Marinhos/microbiologia , Animais , Bactérias Aeróbias/classificação , Bactérias Aeróbias/isolamento & purificação , Contagem de Colônia Microbiana , DNA Bacteriano/análise , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Lactobacillus/classificação , Lactobacillus/isolamento & purificação , Filogenia , RNA Ribossômico 16S/análise , RNA Ribossômico 23S/análise , Ribotipagem , Alimentos Marinhos/normas , Paladar , Temperatura , Fatores de Tempo , Vácuo
19.
Int J Syst Evol Microbiol ; 54(Pt 5): 1621-1626, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15388719

RESUMO

On the basis of phenotypic and DNA-DNA reassociation studies, strain CCUG 34545T has been considered to represent a distinct Lactobacillus curvatus subspecies, Lactobacillus curvatus subsp. melibiosus. However, in several independent studies dealing with Lactobacillus sakei and L. curvatus strains, the subspecies division of L. curvatus has been found to be controversial. The original study distinguishing the two subspecies within both L. curvatus and L. sakei also lacked 16S rRNA gene sequence analyses. Therefore, the taxonomic position of L. curvatus subsp. melibiosus CCUG 34545T was re-evaluated in a polyphasic taxonomy study that included 16S rRNA gene sequence analysis, DNA-DNA reassociation, DNA G + C content determination, numerical analysis of ribotypes and whole-cell protein patterns and the examination of some fundamental phenotypic properties. The results obtained indicate that strain CCUG 34545T and its duplicate, CCUG 41580T, are Lactobacillus sakei subsp. carnosus strains and that L. curvatus subsp. melibiosus is a later synonym of L. sakei subsp. carnosus.


Assuntos
Lactobacillus/classificação , Proteínas de Bactérias/análise , Proteínas de Bactérias/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , DNA Ribossômico/química , DNA Ribossômico/isolamento & purificação , Genes de RNAr , Lactobacillus/genética , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Filogenia , Proteoma/análise , Proteoma/isolamento & purificação , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Ribotipagem , Análise de Sequência de DNA
20.
Int J Syst Evol Microbiol ; 54(Pt 5): 1823-1827, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15388750

RESUMO

Isolates 302, 334, 356, 377 and 379, detected in modified-atmosphere-packaged broiler meat, together with strains LMG 12317T and LMG 13617, detected in dog tonsils, were analysed in a polyphasic taxonomy study, including numerical analysis of ribopatterns and whole-cell protein patterns, 16S rRNA gene sequence analysis, DNA-DNA hybridization and determination of some phenotypic properties. The results indicated that these isolates represent a novel species in the genus Enterococcus. The isolates showed classical phenotypic reactions for the genus Enterococcus with the exception of not possessing the Lancefield group D antigen. Isolates 334, LMG 12317T and LMG 13617 showed the highest 16S rRNA gene sequence similarity (98.3-99.0 %) to the Enterococcus pallens type strain. In the distance matrix tree based on 16S rRNA gene sequences, the three isolates were located in the Enterococcus avium group with E. pallens as their closest phylogenetic neighbour. Numerical analyses of whole-cell protein patterns and HindIII/EcoRI ribotypes placed all seven isolates together in a single cluster separated from the E. avium group reference strains. The DNA-DNA hybridization level between strains 334 and LMG 12317T was 93.5 %, confirming that they represent the same species. Low hybridization levels (12-30 %) were, by contrast, obtained with the E. pallens and Enterococcus raffinosus type strains. The name Enterococcus hermanniensis sp. nov. is proposed, with strain LMG 12317T (= CCUG 48100T) as the type strain.


Assuntos
Enterococcus/classificação , Enterococcus/isolamento & purificação , Carne/microbiologia , Tonsila Palatina/microbiologia , Animais , Antígenos de Bactérias/análise , Proteínas de Bactérias/análise , Proteínas de Bactérias/isolamento & purificação , Técnicas de Tipagem Bacteriana , Galinhas , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , DNA Ribossômico/química , DNA Ribossômico/isolamento & purificação , Cães , Enterococcus/genética , Enterococcus/fisiologia , Microbiologia de Alimentos , Genes de RNAr , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Filogenia , Proteoma/análise , Proteoma/isolamento & purificação , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Ribotipagem , Análise de Sequência de DNA
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